1. Field of the Invention
The present invention relates to cardiac catheter devices and more particularly relates to an improved method and apparatus for cardiac catheter devices utilized in the performance of percutaneous transluminal coronary angioplasty procedures and the like. Even more particularly, the present invention relates to an improved catheter device which allows the exchange of a coronary guiding catheter while the coronary guide wire is left in place and across an obstruction in the coronary artery.
2. General Background
In the mid 1970s, Andreas Gruntzig first used a balloon catheter to percutaneously dilate a stenosis within the coronary artery of a patient with coronary artery disease. Since that time, the utilization of percutaneous transluminal coronary angioplasty has increased significantly. Recently, newer procedures such as coronary stent implantation and coronary atherectomy are being used more and more frequently as an adjunct to coronary angioplasty.
These procedures oftentimes require the use of a larger guiding catheter having a hollow bore. Typically, a guiding catheter with an internal diameter ranging from about 0.060 inches to about 0.080 inches or greater can be utilized. On occasion, the guiding catheter must be exchanged for one of a different distal shape or which is larger in both internal and/or external diameter.
At present such procedures require a removal of the balloon catheter and the coronary guide wire before a new guiding catheter can be placed. After the guiding catheter has been exchanged, the coronary artery and the blockage must be recrossed with the coronary wire. This results in significant risk. Oftentimes, the coronary stenosis has been pre-dilated resulting in intimal flaps and cracks in the wall of the vessel. When recrossing the obstruction, the wire sometimes follows a course underneath the dissection and forms a sub-intimal tract in the wall of the blood vessel.
It is therefore desirable to not recross the obstruction with a coronary guide wire when exchanging the coronary guiding catheter.